[Leica] 85-105 Lens tests

[Jem Kime <jem.kime@cwcom.net>]

Folks,

I found myself with a couple of old rolls of Kchrome 64 and realising their 
colour balance would make real photos an improbability, I decided to 
'waste' them on some lens tests at home.

I used a Paterson lens testing chart which requires shooting from 50x the 
focal length for direct lines per millimetre measurements.
More complex analysis was/is beyond me so please don't feel these results 
are comprehensive in any way.
The figures are taken from 'edge' readings where the chart shows a variety 
of black, red, green and blue lines at various lpm settings near to the 
corner of the frame. The results were assessed via a Pradovit 250 Color and 
both 90 and 50mm Leitz projection lenses.
When two figures are shown, the lower one refers to the finest b/w figure 
seen, the higher to the finest colour figure.
I tested each lens, where practical, at both f2.8 and f5.6. Illumination 
was by flash (in a darkened room) which ensured minimal exposure time for 
sharpness. Camera supported on a (Tiltall) tripod.
Unless otherwise stated lenses wre in fine optical condition with no 
blemishes.

In no particular order...

Steinheil Culminar 85/2.8 (1848904)
2.8	20/28
5.6	48/68

Jupiter 85/2 (7601008)
2.8	34
5.6	48

Staeble Telexon 90/5.6 (669113, slight fungus)
5.6	40

Rokkor-M 90/4 (2011095, Minolta made Rokkor - not Leitz)
5.6	68

(Skinny) Leitz Tele Elmarit 90/2.8 (2727335)
2.8	40
5.6	40

Leitz Summicron 90/2 (2813872, first type compact version 1980+)
2.8	48
5.6	68

Canon 100/4 (91625, late black type, water? damaged coating, looks milky)
5.6	56/68

Canon 100/2 (14564, surface scratches and 2 small chips!)
2.8	68
5.6	68/80

N.O.C. Trinol 105/3.5 (035236, coated)
3.5	28
5.6	48

Soligor 105/4 (H33932)
5.6	56/68

There will be some slight advantage to the longer lenses in that their 
focal length / magnification would naturally increase the visibility of 
lpm. (I did not readjust the shooting distance for them) This will be in 
the order of less than 5% for the 90mm lenses over the 85mm. and c. 10% for 
the 100mm lenses over the 90mm.

Lessons learnt?
It makes me appreciate the work of proper lens testers with their 
multifaceted tests and many more measurements aiming to build up a 
character of the lens in greater depth.
And despite surface condition it suggests that worn lenses may fare better 
than one expects them to.

Jem